xen/arm: Use device tree API in pl011 UART driver

Allow UART driver to retrieve all its information in the device tree.
It's possible to choose the pl011 driver via the Xen command line.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 72 insertions, 16 deletions

diff --git a/xen/drivers/char/pl011.c b/xen/drivers/char/pl011.c
index 8efd08ef22..05b5ef1276 100644
--- a/xen/drivers/char/pl011.c
+++ b/xen/drivers/char/pl011.c
@@ -22,9 +22,16 @@
 #include <xen/serial.h>
 #include <xen/init.h>
 #include <xen/irq.h>
+#include <asm/early_printk.h>
+#include <xen/device_tree.h>
+#include <xen/errno.h>
+#include <asm/device.h>
+#include <xen/mm.h>
+#include <xen/vmap.h>
 
 static struct pl011 {
-    unsigned int baud, clock_hz, data_bits, parity, stop_bits, irq;
+    unsigned int baud, clock_hz, data_bits, parity, stop_bits;
+    struct dt_irq irq;
     volatile uint32_t *regs;
     /* UART with IRQ line: interrupt-driven I/O. */
     struct irqaction irqaction;
@@ -32,7 +39,7 @@ static struct pl011 {
     /* struct timer timer; */
     /* unsigned int timeout_ms; */
     /* bool_t probing, intr_works; */
-} pl011_com[2] = {{0}};
+} pl011_com = {0};
 
 /* PL011 register addresses */
 #define DR     (0x00/4)
@@ -163,13 +170,13 @@ static void __init pl011_init_postirq(struct serial_port *port)
     struct pl011 *uart = port->uart;
     int rc;
 
-    if ( uart->irq > 0 )
+    if ( uart->irq.irq > 0 )
     {
         uart->irqaction.handler = pl011_interrupt;
         uart->irqaction.name    = "pl011";
         uart->irqaction.dev_id  = port;
-        if ( (rc = setup_irq(uart->irq, &uart->irqaction)) != 0 )
-            printk("ERROR: Failed to allocate pl011 IRQ %d\n", uart->irq);
+        if ( (rc = setup_dt_irq(&uart->irq, &uart->irqaction)) != 0 )
+            printk("ERROR: Failed to allocate pl011 IRQ %d\n", uart->irq.irq);
     }
 
     /* Clear pending error interrupts */
@@ -215,7 +222,14 @@ static int pl011_getc(struct serial_port *port, char *pc)
 static int __init pl011_irq(struct serial_port *port)
 {
     struct pl011 *uart = port->uart;
-    return ((uart->irq > 0) ? uart->irq : -1);
+    return ((uart->irq.irq > 0) ? uart->irq.irq : -1);
+}
+
+static const struct dt_irq __init *pl011_dt_irq(struct serial_port *port)
+{
+    struct pl011 *uart = port->uart;
+
+    return &uart->irq;
 }
 
 static struct uart_driver __read_mostly pl011_driver = {
@@ -227,32 +241,74 @@ static struct uart_driver __read_mostly pl011_driver = {
     .tx_ready     = pl011_tx_ready,
     .putc         = pl011_putc,
     .getc         = pl011_getc,
-    .irq          = pl011_irq
+    .irq          = pl011_irq,
+    .dt_irq_get   = pl011_dt_irq,
 };
 
-/* TODO: Parse UART config from device-tree or command-line */
-
-void __init pl011_init(int index, unsigned long register_base_address)
+/* TODO: Parse UART config from the command line */
+static int __init pl011_uart_init(struct dt_device_node *dev,
+                                  const void *data)
 {
+    const char *config = data;
     struct pl011 *uart;
+    int res;
+    u64 addr, size;
 
-    if ( (index < 0) || (index > 1) )
-        return;
+    if ( strcmp(config, "") )
+    {
+        early_printk("WARNING: UART configuration is not supported\n");
+    }
 
-    uart = &pl011_com[index];
+    uart = &pl011_com;
 
     uart->clock_hz  = 0x16e3600;
     uart->baud      = 38400;
     uart->data_bits = 8;
     uart->parity    = PARITY_NONE;
     uart->stop_bits = 1;
-    uart->irq       = 37; /* TODO Need to find this from devicetree */
-    uart->regs      = (uint32_t *) register_base_address;
+
+    res = dt_device_get_address(dev, 0, &addr, &size);
+    if ( res )
+    {
+        early_printk("pl011: Unable to retrieve the base"
+                     " address of the UART\n");
+        return res;
+    }
+
+    uart->regs = ioremap_attr(addr, size, PAGE_HYPERVISOR_NOCACHE);
+    if ( !uart->regs )
+    {
+        early_printk("pl011: Unable to map the UART memory\n");
+
+        return -ENOMEM;
+    }
+
+    res = dt_device_get_irq(dev, 0, &uart->irq);
+    if ( res )
+    {
+        early_printk("pl011: Unable to retrieve the IRQ\n");
+        return res;
+    }
 
     /* Register with generic serial driver. */
-    serial_register_uart(uart - pl011_com, &pl011_driver, uart);
+    serial_register_uart(SERHND_DTUART, &pl011_driver, uart);
+
+    dt_device_set_used_by(dev, DOMID_XEN);
+
+    return 0;
 }
 
+static const char const *pl011_dt_compat[] __initdata =
+{
+    "arm,pl011",
+    NULL
+};
+
+DT_DEVICE_START(pl011, "PL011 UART", DEVICE_SERIAL)
+        .compatible = pl011_dt_compat,
+        .init = pl011_uart_init,
+DT_DEVICE_END
+
 /*
  * Local variables:
  * mode: C